The differences between cloud service models can be confusing. SaaS, PaaS, and IaaS all sound similar even though they are vastly different. The only real similarity is the cloud deployment of these services. Let’s take a closer look at what these models are used for and how you can benefit from them.
What Is a SaaS Model
Software as a Service (SaaS) is the most common and widely used cloud service model. They are either free or have a pay-as-you-go model. In fact, most people already use such platforms. Gmail, Google Docs, and Office 365 are all examples of this type of software. Their other distinguishing characteristic is in the level of control. The vendor is the owner of these services while the user has limited access to their functionality.
The delivery is extremely easy for the user. It works on any platform without any downloads or installations. Services are available directly in a web browser. Among the typical characteristics of this model are their centralized nature, remote server hosting, and lack of manual updates.
- Reduced expenses on installation and integration.
- Quick and easy access.
- Streamlined upgrades.
- No integration support since the service isn’t a part of the internal infrastructure of the organization.
- It may be difficult to stop using the service. Some providers offer payment models that lock you into using their product sometimes without the ability to export the necessary data.
- Potential for data leaks and security breaches.
- There is a lack of customization options.
- The provider has control over the product and its features.
- Limited or locked features.
- Downtime and performance issues. These usually happen at the least opportune times. With SaaS, you can’t do anything about it since it’s fully up to the vendor to provide support and fix any pressing issues.
Examples of such services: Google G Suite, Trello, Salesforce, Dropbox, GitLab, and GitHub. You can also see our case study of a pizza chain SaaS solution and other projects here.
When to use SaaS:
- Personal use. You are most likely already using them every day.
- Small companies or startups in need of a quick launch.
- Small or easy projects that require collaboration.
- Apps that aren’t used regularly.
What Is a PaaS Model
This model allows its users to run, develop, or manage applications. It is easier and often cheaper than building it from scratch but still has all the tools for the full cycle of development.
There are three types of delivery for such platforms:
- Public. A public cloud service where the vendor provides the servers, OS, middleware, storage, and other features to deploy an app. The end-user has limited configuration options. Originally, this was the only intended type of PaaS but with time other forms have also appeared.
- Private. A private cloud service behind the protection of a firewall. It offers you the best security of all of the three options. They can be installed on the premises of an organization and on a private cloud.
- Hybrid. As the name suggests, it combines some elements of both of the previous types.
- Cost-effectiveness. As a middle-ground between SaaS and IaaS, the pricing for this model is also usually somewhere in between.
- It has more advanced functionality than SaaS. It provides the hardware and middleware that is required for advanced tasks.
- Collaboration. The location of the members of the development team doesn’t matter. They can be in the same office, do some of the work remotely, or be spread out across all corners of the world - the PaaS model makes it easy for them to work together.
- Quick time-to-market. It completely eliminates the time needed to set up an entire infrastructure. This makes integration quicker and easier.
- Focus on the tasks at hand, while the back-end processes are handled by the vendor.
- Supports different programming languages. You don’t have to adapt to the language of the model.
- Americans with Disabilities Act (ADA) compliance.
- Limited control over the vast majority of back-end processes. Operational features are sacrificed for convenience.
- Expensive at large scale. This makes scalability quite limited. You need to pay extra for each individual user or contributor.
- Security issues. You completely entrust all of your data to the provider. If the protocols are breached or data gets lost you are completely out of luck.
- Focus on specific narrow areas and lack of general-purpose solutions. This puts the usefulness of the model into question for most enterprises.
- Vendor lock-in. Software developed on platforms as a service are forever dependent on it for future updates. It is difficult to migrate your projects to other providers. Additionally, some elements can be incompatible with the cloud platform.
Examples of such services: Google App Engine, Windows Azure, AWS Elastic Beanstalk, Apache Stratos, Heroku, OpenShift.
When to use PaaS:
- Software development at any level.
- When you have a specific development task that doesn’t require infrastructure.
- When you want to test an idea or experiment with a potential project.
- A midsize company that doesn’t need to invest in IaaS yet.
What Is an IaaS Model
The IaaS model provides you with virtualized computing resources than can completely replace on-premises infrastructure. This includes storage, servers and networking resources. The payment model is often also pay-as-you-go. There are services that charge either for time or for the use of virtual machine space. As a result, this model is quite popular among IT administrators and organizations that don’t want to invest in expensive hardware. It’s also the most secure and the most scalable option out of the three.
- Complete control over the entire environment with all of its aspects.
- A complete functional infrastructure without any expenses on hardware or in-house software.
- Flexibility. It allows you to experiment with your projects without needing to invest in the creation of complete infrastructure on your premises.
- Security. Nobody but you can access the data you store on IaaS. Even though it is stored on the vendor’s server its safety is guaranteed.
- Scalability. You don’t have the limits of the previously discussed models with this option. The resources are configured and allocated according to demand. More users mean more resources and vice versa.
- It’s noticeably more expensive than the other two models even at a basic level.
- It is your responsibility to maintain the virtual machine with all of its components. As a result, it can take up more of your time and energy.
- The storage of data on remote servers can be considered a security risk regardless of the guarantees of the vendor.
- Poor support of legacy applications. Cloud infrastructures often aren’t designed for that functionality.
Examples of such services: Amazon Web Services (AWS), Rackspace, DigitalOcean, Linode, Google Compute Engine (GCE).
When to use IaaS:
- IT administration purposes.
- Website or application hosting.
- Virtual data centers.
- Complex data analysis.
- Rapidly growing companies with the need for scalability.
So, What Cloud Service Model to Choose?
As you may have guessed the answer depends on what your intended use is. If you are an end-user who just wants access to basic functionality, go for the SaaS model. If you are a software or web developer who needs a coding environment with tools that will help, choose PaaS. Last but not least, if you require virtual machines for the purposes of hosting, testing, or whatever else, go with IaaS. Any of the three cloud service models is a perfectly viable choice for a company looking for digital transformation. However, their uses are so different that it’s hard to define one clear winner.